Systems and methods for controlling liquid flow to a turbine fogging array

ABSTRACT

Methods and apparatus for controlling liquid flow to a turbine fogging array. Some implementations are generally directed toward adjusting the output of a variable output pump that supplies water to the turbine fogging array. In some of those implementations, the output is adjusted based on a determined target pump output value that is indicative of a pump output required to change the moisture content of intake air of a combustion turbine to meet a target humidity value. Some implementations are generally directed toward actuating at least one control valve of a plurality of control valves that control liquid throughput to one or more fogging nozzles of a fogging array.

BACKGROUND

Combustion turbines bring in fresh ambient air, mix the fresh ambientair with fuel in a combustion chamber, and ignite the air-fuel mixture.This produces a high-temperature and high-pressure flow of exhaust gasesthat produce the shaft work output that is generally used to move anelectric generator. The fresh ambient air is typically brought inthrough an inlet housing structure that may include one or more filtersand/or other components.

The performance of the combustion turbine is dependent on the conditionsof the air that is mixed with the fuel in the combustion turbine. Forexample, the amount of fuel that can be contained in an air-fuel mixtureis dependent on the density of the air, which in turn is dependent onrelative humidity, altitude, pressure drop, and temperature.

Fogging is utilized in some combustion turbine installations to reducethe temperature of air supplied to the combustion turbine. Generally,fogging supplies liquid (e.g., water) to an array of fogging nozzleslocated upstream of the turbine compressor blades. The fogging arrayintroduces a spray of the water to thereby reduce inlet air temperature.The fogging array may be positioned, for example, in the inlet housingstructure. For instance, the fogging array may be positioned downstreamof the filter stage in the inlet housing structure. In someimplementations, to reduce the amount of moisture that reaches thecombustion turbine, condensers and/or other moisture eliminators may beprovided downstream of the fogging array, but upstream of the combustionturbine.

SUMMARY

This specification is directed generally to methods and apparatus forcontrolling liquid flow to a turbine fogging array. The methods andapparatus described herein may, in some implementations, provide forliquid flow to the turbine fogging array that is adapted to particularweather conditions, adapted to a particular mass flow rate of intake airof the combustion turbine, and/or adapted to a particular wear conditionof a pump that supplies the liquid flow to the turbine fogging array.Such adaptations may minimize a degree of, and/or frequency ofoccurrence of, undersupply and/or oversupply of liquid to the turbinefogging array. The methods and apparatus described herein may, in someimplementations, actuate one or more control valves that each controlliquid throughput to one or more fogging nozzles of the fogging array.In some of those implementations, the control valves may be actuatedbased on desired and actual water pressure values downstream of the pumpto allow for improved water pressure control under varying conditionssuch as varying pump conditions, and/or varying system leakage and/orblockage conditions.

Some implementations are generally directed toward adjusting the outputof a variable output pump that supplies water to the turbine foggingarray. In some of those implementations, the output is adjusted based ona determined target pump output value that is indicative of a pumpoutput required to change the moisture content of intake air of thecombustion turbine to meet a target humidity value such as, for example,a 100% target relative humidity value. In some of those implementations,the target pump output value may be determined based on data from one ormore sensors such as one or more weather sensors and/or one or moreturbine mass flow sensors. In some of those implementations, the outputof the pump may be further adjusted based on feedback from a flow ratesensor located downstream of the pump and in the path of the liquidsupplied by the pump.

Some implementations are generally directed toward actuating at leastone control valve of a plurality of control valves that control liquidthroughput to one or more fogging nozzles of a fogging array. In some ofthose implementations, the at least one control valve is actuated basedon comparing an anticipated pressure value for liquid in a conduitbetween a pump and a fogging array to a measured actual pressure valuein the conduit. In some versions of those implementations, the controlvalves may be actuated to increase or decrease the actual pressure valueand make it more conforming to the anticipated pressure value.

In some implementations, a method of adjusting pump output of a pumpsupplying liquid to a fogging array positioned upstream of a combustionturbine may be provided that includes: receiving weather sensor dataindicative of one or more weather conditions of intake air of thecombustion turbine; identifying a target humidity value for the intakeair; determining, based on the weather sensor data and the targethumidity value, a target pump output value indicative of a pump outputrequired to change the moisture content of the intake air to meet thetarget humidity value; and adjusting the output of a variable outputpump based on the target pump output value, the variable output pumpsupplying liquid to a fogging array positioned upstream of thecombustion turbine.

In some implementations, a system for controlling output of a foggingarray positioned upstream of a combustion turbine may be provided thatincludes: one or more weather sensors measuring one or more conditionsof intake air of the combustion turbine and providing weather sensordata responsive to the measurements, the weather sensor data enablingdetermination of relative humidity of the intake air; a variable outputpump supplying liquid to a fogging array positioned upstream of thecombustion turbine, the variable output pump operable at a plurality ofspeeds; memory storing instructions; a controller receiving the weathersensor data and coupled to a drive for the pump, the controller operableto execute the instructions stored in the memory; wherein theinstructions comprise instructions to: identify a target humidity valuefor the intake air; determine, based on the weather sensor data and thetarget humidity value, a target pump output value indicative of a pumpoutput required to change the moisture content of the intake air to meetthe target humidity value; and adjust the speed for the variable outputpump based on the target pump output value.

In some implementations, a method of adjusting pump output of a pumpsupplying liquid to a fogging array positioned upstream of a combustionturbine may be provided that includes: receiving weather sensor dataindicative of one or more weather conditions of intake air of thecombustion turbine; determining a target pump output value based on theweather sensor data; adjusting the output of a variable output pumpbased on the target pump output value, the variable output pumpsupplying liquid to a fogging array positioned upstream of thecombustion turbine; receiving flow rate sensor data from a flow ratesensor, the flow rate sensor located downstream of the pump and in apath of the liquid supplied by the pump; and further adjusting theoutput of the variable output pump based on the flow rate sensor dataand the target pump output value.

In some implementations, a method of adjusting pump output of a pumpsupplying liquid to a fogging array positioned upstream of a combustionturbine may be provided that includes: receiving weather sensor dataindicative of one or more weather conditions of intake air of thecombustion turbine; receiving turbine mass flow data indicative of amass flow rate of the intake air; determining a target pump output valuebased on the weather sensor data and the mass flow data; and adjustingthe output of a variable output pump based on the target pump outputvalue, the variable output pump supplying liquid to a fogging arraypositioned upstream of the combustion turbine.

The term “controller” is used herein generally to describe variousapparatus relating to the operation of one or more fluid pumps and/orcontrol valves. A controller can be implemented in numerous ways (e.g.,such as with dedicated hardware) to perform various functions discussedherein. A “processor” is one example of a controller which employs oneor more microprocessors that may be programmed using software (e.g.,microcode) to perform various functions discussed herein. A controllermay be implemented with or without employing a processor, and also maybe implemented as a combination of dedicated hardware to perform somefunctions and a processor (e.g., one or more programmed microprocessorsand associated circuitry) to perform other functions. Examples ofcontroller components that may be employed in various embodiments of thepresent disclosure include, but are not limited to, conventionalmicroprocessors, application specific integrated circuits (ASICs), andfield-programmable gate arrays (FPGAs).

In various implementations, a processor or controller may be associatedwith one or more storage media (generically referred to herein as“memory,” e.g., volatile and non-volatile computer memory such as RAM,PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks,magnetic tape, etc.). In some implementations, the storage media may beencoded with one or more programs that, when executed on one or moreprocessors and/or controllers, perform at least some of the functionsdiscussed herein. Various storage media may be fixed within a processoror controller or may be transportable, such that the one or moreprograms stored thereon can be loaded into a processor or controller soas to implement various aspects of the present invention discussedherein. The terms “program” or “computer program” are used herein in ageneric sense to refer to any type of computer code (e.g., software ormicrocode) that can be employed to program one or more processors orcontrollers.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts described in greater detail herein arecontemplated as being part of the subject matter disclosed herein. Forexample, all combinations of claimed subject matter appearing at the endof this disclosure are contemplated as being part of the subject matterdisclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example environment in which liquid flow to aturbine fogging array may be controlled.

FIG. 2 illustrates an example of using various inputs to determine atarget pump output value and adjusting a pump output based on the targetpump output value.

FIG. 3 illustrates another example of using various inputs to determinea target pump output value and adjusting a pump output based on thetarget pump output value.

FIG. 4 illustrates an example of actuating one or more control valvesbased on an anticipated pressure value and an actual pressure value.

DETAILED DESCRIPTION

FIG. 1 illustrates an example environment in which liquid flow to aturbine fogging array may be controlled. The example environment of FIG.1 includes intake air 101 (e.g., ambient air) that is drawn into aninlet housing 103 by the rotating blades of a combustion turbine 105,such as a gas combustion turbine. The intake air 101 is communicatedthrough inlet housing 103 and into the combustion turbine 105. Thecombustion turbine 105 mixes the intake air 101 with fuel in acombustion chamber, and ignites the air-fuel mixture. This produces ahigh-temperature and high-pressure flow of exhaust gases that producethe shaft work output of the combustion turbine 105 that is generallyused to move an electric generator.

The inlet housing 103 may include one or more filters (e.g., at an“intake” end of the inlet housing 103). The inlet housing 103 mayfurther optionally house and/or support one or more additionalcomponents such as fogging arrays (145A-145C), inlet housing weathersensor 135, and/or turbine mass flow sensor 137. Components 145A-C, 135,and 137 are illustrated in FIG. 1 surrounded by dashed lines andconnected to inlet housing 103 with solid lines to indicate at leastthose components may be housed in and/or supported by inlet housing 103.One or more other components of FIG. 1 may also be housed in and/orsupported by inlet housing 103 in some implementations, or may bepositioned spaced away from inlet housing 103 in some implementations.

Generally, a variable output pump 150 pulls water through one or moreconduits coupled to a water supply 107 and supplies the water throughone or more conduits to one or more downstream fogging arrays 145A-C.The fogging arrays 145A-C are positioned in the inlet housing 103 andintroduce a spray of the water in the inlet housing 103 to therebyreduce the temperature of the intake air 101 before it is supplied tothe combustion turbine 105. Although three fogging arrays 145A-C areillustrated in the example of FIG. 1, more or fewer fogging arrays maybe provided. In some implementations, the water supply 107 may be ademineralized water supply. In some implementations, a filter 109 may beinterposed between the water supply 107 and the variable output pump 150to filter one or more particulates from the water supply 107.

Various sensors are provided in the example environment of FIG. 1. Thesensors include: a pressure sensor 131 measuring pressure in a conduitbetween the water supply 107 and the variable output pump 150; atemperature sensor 132 measuring temperature of water in the conduitbetween the water supply 107 and the variable output pump 150; a flowsensor 133 measuring flow rate of fluid in a conduit between thevariable output pump 150 and the fogging arrays 145A-C; and a pressuresensor 134 measuring pressure in a conduit between the variable outputpump 150 and the fogging arrays 145A-C.

The sensors further include an inlet housing weather sensor 135measuring one or more weather conditions such as temperature and/orhumidity. For example, the inlet housing weather sensor 135 may compriseone or more sensors that collectively measure both temperature and watercontent of air and provide data indicative of both and/or dataindicative of a relative humidity determined based on both. The inlethousing weather sensor 135 may be positioned within the inlet housing103 and exposed to airflow through the inlet housing 103. For example,the sensor 135 may be positioned downstream of the fogging arrays145A-C, such as at a location just before the combustion turbine 105.

The sensors further include an ambient weather sensor 136 measuring oneor more weather conditions such as temperature and/or humidity. Forexample, the ambient weather sensor 136 may comprise one or more sensorsthat collectively measure both temperature and water content of air andprovide data indicative of both and/or data indicative of a relativehumidity determined based on both. The ambient weather sensor 136 may bepositioned to measure ambient air before it interacts with water sprayoutput from the fogging arrays 145A-C. For example, the ambient weathersensor 136 may be positioned external to the inlet housing 103, orwithin the inlet housing 103 positioned upstream of the fogging arrays145A-C, such as at a location just before filters of the inlet housing103.

The sensors further include turbine mass flow sensor 137 measuring themass flow rate of air. For example, the sensor 137 may provide dataindicative of weight of air over a period of time. The turbine mass flowsensor 137 may be positioned to measure a mass flow rate of air beingpulled in by the combustion turbine 105. For example, the sensor 137 maybe positioned within the inlet housing 103, such as at a location justbefore the combustion turbine 105.

Particular sensors are illustrated in the example environment of FIG. 1and are illustrated and/or described as being positionable in particularlocations. However, in some implementations one or more of the sensorsmay be omitted and/or repositioned. For example, in some implementationsthe flow sensor 133 may be positioned upstream of the variable outputpump 150. For example, it may be positioned right before the intake ofthe variable output pump 150. As another example, in someimplementations, one or more of the ambient weather sensor 136, theturbine mass flow sensor 137, the pressure sensor 131, the temperaturesensor 132, the flow sensor 133, and/or the pressure sensor 134 may beomitted.

Generally, the controller 120 receives sensor data from one or moresensors (e.g., sensors 131-137 of FIG. 1) and, based at least in part onthe sensor data, adjusts the output of the variable output pump 150and/or actuates one or more of the control valves 140A-C. For example,controller 120 may determine a target pump output value based on sensordata from inlet housing weather sensor 135, ambient weather sensor 136,and/or turbine mass flow sensor 137 and adjust the variable output pump150 based on the target pump output value. Additional description isprovided in FIGS. 2-4 of example sensor data, and example uses of sensordata in adjusting the output of the variable output pump 150 and/oractuating one or more of the control valves 140A-C.

The variable output pump 150 is configured to produce a plurality ofdistinct outputs (e.g., variable speeds and/or variable types ofrotations, displacements, reciprocations, etc.). Adjusting the output ofthe variable output pump 150 adjusts the resulting flow rate of liquidthat is pumped by the variable output pump 150. For example, thevariable output pump 150 may have a discrete number of speeds at whichthe pump may operate and the flow rate may be distinct at each of theplurality of speeds. Also, for example, the variable output pump 150 maybe continuously variable between a minimum and a maximum speed, and oneor more of the variable speeds may produce a distinct flow rate.

The controller 120 may provide various types of output to adjust theoutput of the variable output pump 150. For example, the variable outputpump 150 may be driven by an AC motor that is controlled by a variablefrequency drive and the controller 120 may provide a control signal tothe variable frequency drive that dictates the driving characteristicsthat should be applied to the AC motor (and that will resultantly affectthe speed of the pump).

The control valves 140A-C are each actuable between at least a firstposition and a second position. For example, the control valves 140A-Cmay each be actuable between at least an “open” position and a “closed”position. Each of the control valves 140A-C may be coupled to anactuator that actuates the control valve between at least the onposition and the off position. The controller 120 may individuallycontrol each of the actuators. For example, each of the actuators may beassociated with an address and the controller 120 may send an actuationsignal that is addressed to one or more of the actuators. Generally, thecontroller 120 utilizes one or more inputs, such as inputs from pressuresensor 131 and/or pressure sensor 134 to determine which of the controlvalves 140A-C should be opened, and which should be closed (if any).Although three control valves 140A-C are illustrated in the example ofFIG. 1, more or fewer control valves may be provided. For example, asingle control valve may control multiple fogging arrays and/oradditional fogging arrays and corresponding control valves may beprovided.

Referring to FIG. 2, an example is provided of using various inputs todetermine a target pump output value and adjusting a pump output basedon the target pump output value. FIG. 2 is described with respect tosteps that may be performed by, for example, the controller 120. Otherimplementations may perform the steps in a different order, omit certainsteps, and/or perform different and/or additional steps than thoseillustrated in FIG. 2.

At step 151, a target pump output value is determined based on one ormore sensor inputs. As one example, the ambient weather sensor 136 andthe turbine mass flow sensor 137 may each provide sensor data to thecontroller 120 and the controller 120 may determine the target pumpvalue based on such sensor data. As described herein, the sensor dataprovided by ambient weather sensor 136 may indicate relative humidityalone and/or may indicate temperature value and a humidity value. Asalso described herein, the sensor data provided by turbine mass flowsensor 137 may indicate a mass flow rate of the intake air beingprovided to the combustion turbine. In some implementations, the turbinemass flow sensor 137 may be omitted and a preset mass flow rate may beutilized. The preset mass flow rate may be set, for example, duringcommissioning and/or programming of the controller 120 and may be basedon one or more characteristics of the combustion turbine 105. Forexample, the mass flow rate may be set based on determined performancedata for the combustion turbine 105.

In some implementations, the controller 120 may determine the targetpump output value based on a formula that takes into account an ambienttemperature, an ambient humidity, and a mass flow rate of the intakeair. For example, the formula may generally increase the target pumpoutput value (where an increasing value indicates increasing pumpoutput) as the ambient temperature increases and the mass flow rate ofthe intake air increases. The formula may further set a maximum for thetarget pump output value based on the ambient humidity. For example, asthe ambient humidity increases, the maximum for the target pump outputvalue may decrease (where a decreasing value indicates decreasing pumpoutput). Accordingly, based on such a formula the target pump outputvalue will increase as the temperature and mass flow rate increase, butwill be capped based on the humidity (since humidity limits the lowesttemperature to which air can be cooled, this cap will minimizeoversaturation and/or wasted water).

As another example of a formula that takes into account an ambienttemperature, an ambient humidity, and a mass flow rate of the intakeair, the formula may determine, based on the ambient temperature and theambient humidity, how much more water vapor mass would fit in a givenmass of air to reach a desired relative humidity level such as 100%. Forexample, a formula that subtracts the specific humidity of the air froma target humidity level may be utilized. The formula may further modifysuch determination based on the mass flow rate of the intake air todetermine a quantity of water vapor that would be needed for a giventime to reach the desired relative humidity level, and utilize suchdetermination to determine the target pump output value. For instance,the target pump output value would be set to a value that would outputapproximately the quantity of water vapor over the given time period.Formulae, tables, and/or other data structures may map target pumpoutput values to quantities of water vapor for one or more time periodsand may be utilized by the controller 120 in determining a target pumpoutput value based on a quantity of water vapor for a given time period.In some other implementations, the target pump output value itself maybe expressed as a quantity of water vapor.

As yet another example, the inlet housing weather sensor 135 and theturbine mass flow sensor 137 may each provide sensor data to thecontroller 120 and the controller 120 may determine the target pumpvalue based on such sensor data. An example of the controller 120determining the target pump value based on such sensor data is describedin more detail with respect to FIG. 3.

Additional and/or alternative formulae may be utilized to determine atarget pump output value. For example, a formula that takes into accounta temperature of the liquid provided to the variable output pump 150(e.g., as indicated by sensor data of temperature sensor 132) and/or apressure of the liquid provided to the variable output pump 150 (e.g.,as indicated by pressure sensor 131) may be utilized. Also, in someimplementations a table may be stored in memory accessible by thecontroller 120 and may include target pump output values mapped to oneor more input variables. Such a table may be accessed by controller 120to determine a target pump output value. For example, the table may besearched based on received sensor data to determine a target pump outputvalue.

At step 152, the pump is adjusted based on the target pump output valuedetermined at step 151. For example, the variable output pump 150 may bedriven by an AC motor that is controlled by a variable frequency driveand the controller 120 may provide a control signal to the variablefrequency drive that dictates the driving characteristics that should beapplied to the AC motor to achieve the target pump output value. In someimplementations, formulae, tables, and/or other data structures may maptarget pump output values to corresponding control signals and may beutilized by the controller 120 in determining control signals to providefor adjusting the pump output of the variable output pump 150.

At optional step 153, the target pump output value is compared to anactual pump output value as indicated by sensor data from flow sensor133. For example, the target pump output value may be indicative of adesired flow rate and may be compared to an actual flow rate asindicated by sensor data from flow sensor 133. At optional step 154,further adjustments are made to the pump output based on the comparisonof step 153. For instance, if the actual flow rate is less than thedesired flow rate, the pump output may be increased in an attempt toachieve the desired flow rate. On the other hand, if the actual flowrate is greater than the desired flow rate, the pump output may bedecreased in an attempt to achieve the desired flow rate. The degree towhich the pump output is increased or decreased may be correlated to thedifference between the desired flow rate and the actual flow rate. Forexample, the output may be affected to a greater degree if thedifference is 5 gallons per minute than if the difference was only 3gallons per minute.

In some implementations, steps 153 and 154 may be performed iterativelyby the controller 120. For example, the steps 153 and 154 may beperformed until a difference between the desired flow rate and theactual flow rate is less than a threshold value and/or until a maximumnumber of iterations are performed. In some implementations, thecontroller 120 may not further adjust the pump output at step 154 unlessthe difference between the desired flow rate and the actual flow ratesatisfies a threshold such as, for example, 0.1 gallons per minute.

After the pump is adjusted by the controller 120 at step 152 and/orfurther adjusted at step 154, the controller 120 may again determine atarget pump output value based on one or more sensor outputs at step 151(optionally after a timeout period). If the target pump output value isdifferent than the previously determined pump output value, thecontroller 120 may again at step 152 adjust the pump output based on thetarget pump output value. The steps 151, 152, and optional steps 153 and154 may be iteratively performed to dynamically adjust the pump outputas one or more conditions sensed by one or more sensors change.

Referring to FIG. 3, another example is provided of using various inputsto determine a target pump output value and adjusting a pump outputbased on the target pump output value. FIG. 3 is described with respectto steps that may be performed by, for example, the controller 120.Other implementations may perform the steps in a different order, omitcertain steps, and/or perform different and/or additional steps thanthose illustrated in FIG. 3.

At step 161, a target humidity value is identified. The target humidityvalue may be, for example, a target relative humidity value such as 90%,95%, or 100% relative humidity. The target humidity value may be storedin memory accessible by the controller 120 and may optionally beadjusted based on operator input and/or based on one or more factors,such as ambient temperature (as indicated by ambient weather sensor 136)and/or inlet housing temperature (as indicated by inlet housing weathersensor 135).

At step 162, a change in moisture content required to meet the targethumidity level is determined. For example, the controller 120 mayutilize sensor data from ambient weather sensor 136 to determine adifference between the ambient humidity and the target humidity value.The difference may be identified as the change in moisture contentrequired to meet the target humidity level. Also, for example, thecontroller 120 may utilize sensor data from inlet housing weather sensor135 to determine a difference between the humidity of the inlet housing103 and the target humidity value. The difference may be identified asthe change in moisture content required to meet the target humiditylevel.

At step 163, a target pump output value required to meet the targethumidity value is determined. For example, when the target humiditylevel is based on the sensor data from the ambient weather sensor 136,the target pump output value may be determined based on identifying thepump output required to achieve the change in moisture content andutilizing that pump output as the target pump output value. Forinstance, where the change in moisture content is expressed as aquantity of water vapor for a period of time, the target pump outputvalue may be set to deliver approximately that quantity of water vaporfor the period of time. The controller may optionally determine thequantity of water vapor needed for a period of time based on turbinemass flow rate data as described herein (e.g., based on sensor data fromturbine mass flow sensor 137).

As another example, when the target humidity level is based on thesensor data from the inlet housing weather sensor 135, the target pumpoutput value may be determined based on identifying the pump outputrequired to achieve the change in moisture content and utilizing as thetarget pump output value, that pump output added to the current pumpoutput. In other words, the controller 120 will determine to what extentthe current pump output needs to be increased to achieve the targethumidity level. For instance, where the change in moisture content isexpressed as a quantity of water vapor for a period of time, the targetpump output value may be set to add to the current pump output, whateveradditional pump output is needed to deliver approximately that quantityof water vapor for the period of time. The controller 120 may optionallydetermine the quantity of water vapor needed for a period of time basedon turbine mass flow rate data as described herein (e.g., based onsensor data from turbine mass flow sensor 137).

At step 164, the pump is adjusted based on the target pump output valuedetermined at step 163. For example, the variable output pump 150 may bedriven by an AC motor that is controlled by a variable frequency driveand the controller 120 may provide a control signal to the variablefrequency drive that dictates the driving characteristics that should beapplied to the AC motor to achieve the target pump output value. Atoptional step 165, the target pump output value is compared to an actualpump output value as indicated by sensor data from flow sensor 133. Forexample, the target pump output value may be indicative of a desiredflow rate and may be compared to an actual flow rate as indicated bysensor data from flow sensor 133. At optional step 166, furtheradjustments are made to the pump output based on the comparison of step165. For instance, if the actual flow rate is less than the desired flowrate, the pump output may be further increased in an attempt to achievethe desired flow rate. In some implementations, the steps 165 and 153may be performed iteratively by the controller 120. For example, thesteps 165 and 166 may be performed until a difference between thedesired flow rate and the actual flow rate is less than a thresholdvalue and/or until a maximum number of iterations are performed. Steps164-166 of FIG. 3 may share one or more aspects in common with steps152-154 of FIG. 2. Also, steps 161-163 of FIG. 3 may share one or moreaspects in common with step 151 of FIG. 2.

After the pump is adjusted by the controller at step 164 and/or furtheradjusted at step 166, the controller 120 may again determine a targetpump output value based on one or more sensor outputs at step 162(optionally after a timeout period). If the target pump output value isdifferent than the previously determined pump output value, thecontroller 120 may progress through the other steps. The steps 161-166may be iteratively performed to dynamically adjust the pump output asone or more conditions sensed by one or more sensors change.

FIG. 4 illustrates an example of actuating one or more control valvesbased on an anticipated pressure value and an actual pressure value.FIG. 4 is described with respect to steps that may be performed by, forexample, the controller 120. Other implementations may perform the stepsin a different order, omit certain steps, and/or perform differentand/or additional steps than those illustrated in FIG. 4. In someimplementations, the example of FIG. 4 may be performed in combinationwith one or more of the examples described with respect to FIGS. 2 and3. In other implementations, the example of FIG. 4 may be performedindependently of the examples described with respect to FIGS. 2 and 3.

At step 171, an anticipated pressure value is determined based on one ormore values. For example, the controller 120 may determine ananticipated pressure value for a conduit between the variable outputpump 150 and the fogging arrays 145A-C based on a current pump output141 and/or the current status 143 of one or more control valves 140A-C.For example, data in memory accessible by the controller 120 may define,for each of a plurality of pump outputs, anticipated pressure values.Also, for example, data in memory accessible by the controller 120 maydefine, for each of a plurality of pump outputs and a plurality of valvestatuses, anticipated pressure values. For example, a pressure of X maybe associated with a “full” pump output of variable output pump 150 andall valves 140A-C being open, whereas a pressure of Y may be associatedwith “half” pump output of variable output pump 150 and all valves140A-C being open and a pressure of Z may be associated with a “full”pump output of variable output pump 150 and two of the three valves140A-C being open. In some implementations, the controller 120 maydetermine the anticipated pressure also based on sensor data provided bythe temperature sensor 132 (to account for differences in pressure thatmay be due to temperature changes).

In some implementations, the anticipated pressure values may be set, forexample, during commissioning and/or programming of the controller 120.For example, in some implementations the anticipated pressure value fora “full” pump output of variable output pump 150 and all valves 140A-Cbeing open may be determined based on a measured pressure value (e.g.,based on sensor data from pressure sensor 134) under those conditionsduring commissioning. The anticipated pressure value may be manuallyand/or automatically stored in memory accessible by the controller 120.

At step 172, an actual pressure value is determined based on one or morepressure sensors such as pressure sensor 134 and/or pressure sensor 131.For example, the controller 120 may determine the actual pressure basedon sensor data provided by pressure sensor 134.

At step 173, one or more of the control valves 140A-C are actuated basedon the anticipated pressure value and the actual pressure value. Forexample, when the actual pressure value is greater than the anticipatedpressure value, the controller 120 can cause one or more of the controlvalves 140A-C that are in a closed position to be moved to an openposition. Also, for example, when the actual pressure value is greaterthan the anticipated pressure value, the controller 120 can cause one ormore of the control valves 140A-C that are in a partially open positionto be moved to more open position. As yet another example, when theactual pressure value is less than the anticipated pressure value, thecontroller 120 can cause one or more of the control valves 140A-C thatare in an open position to be moved to a closed position. The number ofcontrol valves 140A-C actuated and/or the extent of the actuation may bedependent on the difference between the actual pressure value and theanticipated pressure value. In some implementations, the controller 120may not actuate one or more of the control valves 140A-C at step 173unless the difference between the anticipated pressure value and theactual pressure value satisfies a threshold.

In some implementations, steps 172 and 173 may be performed iterativelyby the controller 120. For example, the steps 172 and 173 may beperformed until a difference between the anticipated pressure value andthe actual pressure value is less than a threshold value and/or until amaximum number of iterations are performed. In some of thoseimplementations, the control valves that are actuated and/or the degreeof actuation of those control valves may vary in one or more of theiterations. For example, the controller 120 may, at a first iterationactuate control valve 140A from an open position to a closed positionthen, at a second iteration, actuate the control valve 140A from theclosed position back to the open position and actuate the control valve140B from an open position to a closed position. Varying which controlvalves are actuated (and/or a degree of the actuation(s)) on multipleiterations may enable a blockage and/or a leakage condition to beameliorated.

As one example, assume a leak is present in fogging array 145B and thatall of the control valves 140A-C are initially in an open position.Under such a scenario, the actual pressure may be significantly lessthan the anticipated pressure value due to the presence of the leak. Ata first iteration, the controller 120 may actuate the control valve 140Ato a closed position and maintain the open position of the other controlvalves 140B and 140C. At a second iteration, the controller 120 maydetermine the actual pressure value is still significantly less than theanticipated pressure value (since the control valve 140B is still openthat feeds the fogging array 145B with a leak). At the second iteration,the controller 120 may actuate the control valve 140A to an openposition and actuate the control valve 140B to a closed position. At thethird iteration, the controller 120 may determine the actual pressurevalue is not significantly less than the anticipated pressure value(since the control valve 140B that feeds the fogging array 145B with aleak was closed in the second iteration). Based on such a determination,the controller 120 may not make any further adjustments to the controlvalves 140A-C. In some of those implementations, the controller 120 mayinitiate an audible and/or visible alert to notify an operator of thepresence of a leak condition and/or a location of the leak condition. Insome of those implementations, where the controller 120 is unable tocause an actual pressure value to be within an anticipated pressurevalue after one or more iterations, the controller 120 may shut down thevariable output pump 150 and/or may initiate an audible and/or visiblealert to notify an operator of the presence of a leakage or blockagecondition.

While several implementations have been described and illustratedherein, a variety of other means and/or structures for performing thefunction and/or obtaining the results and/or one or more of theadvantages described herein may be utilized, and each of such variationsand/or modifications is deemed to be within the scope of theimplementations described herein. More generally, all parameters,dimensions, materials, and configurations described herein are meant tobe exemplary and that the actual parameters, dimensions, materials,and/or configurations will depend upon the specific application orapplications for which the teachings is/are used. Those skilled in theart will recognize, or be able to ascertain using no more than routineexperimentation, many equivalents to the specific implementationsdescribed herein. It is, therefore, to be understood that the foregoingimplementations are presented by way of example only and that, withinthe scope of the appended claims and equivalents thereto,implementations may be practiced otherwise than as specificallydescribed and claimed. Implementations of the present disclosure aredirected to each individual feature, system, article, material, kit,and/or method described herein. In addition, any combination of two ormore such features, systems, articles, materials, kits, and/or methods,if such features, systems, articles, materials, kits, and/or methods arenot mutually inconsistent, is included within the scope of the presentdisclosure.

What is claimed is:
 1. A system for controlling output of a foggingarray positioned upstream of a combustion turbine, the systemcomprising: one or more weather sensors measuring one or more conditionsof intake air of the combustion turbine and providing weather sensordata responsive to the measurements, the weather sensor data enablingdetermination of relative humidity of the intake air; a variable outputpump supplying liquid to the fogging array positioned upstream of thecombustion turbine, the variable output pump operable at a plurality ofspeeds; memory storing instructions; a controller receiving the weathersensor data and coupled to a drive for the pump, the controllerconfigured to execute the instructions stored in the memory; wherein theinstructions comprise instructions to: identify a target humidity valuefor the intake air; determine, based on the weather sensor data and thetarget humidity value, a target pump output value indicative of a pumpoutput required to change the moisture content of the intake air to meetthe target humidity value; adjust the speed for the variable output pumpbased on the target pump output value; determine presence of a leakagecondition, wherein the instructions to determine presence of the leakagecondition comprise instructions to: actuate a plurality of controlvalves into a plurality of configurations in which at least one controlvalve of the plurality of control valves is in an open position for eachof the plurality of configurations, each of the plurality of controlvalves controlling liquid throughput to one or more correspondingnozzles of the fogging array, for each of the plurality ofconfigurations, compare an actual pressure value, for the liquid in aconduit between the variable output pump and the fogging array, to ananticipated pressure value, and determine the presence of the leakagecondition is at a particular control valve, of the control valves, basedon at least one of the comparisons between the actual pressure value andthe anticipated pressure value; and in response to determining thepresence of the leakage condition is at the particular control valve,actuate the particular control valve into an at least partially closedposition.
 2. The system of claim 1, further comprising: a temperaturesensor measuring temperature of the liquid and generating temperaturesensor data, the temperature sensor located upstream of the variableoutput pump and measuring the temperature of the liquid before theliquid encounters the variable output pump; wherein the instructions todetermine the target pump output value further comprise instructions todetermine the target pump output value further based on the temperaturesensor data.
 3. The system of claim 1, further comprising: a flow ratesensor located downstream of the variable output pump and in the path ofthe liquid supplied by the pump, the flow rate sensor measuring flow ofthe liquid and providing flowrate sensor data to the controller; whereinthe instructions to determine the target pump output value furthercomprise instructions to determine the target pump output value furtherbased on the flow rate sensor data.
 4. The system of claim 3, furthercomprising: a temperature sensor measuring temperature of the liquid andgenerating temperature sensor data, the temperature sensor locatedupstream of the variable output pump and measuring the temperature ofthe liquid before the liquid encounters the variable output pump;wherein the instructions to determine the target pump output valuefurther comprise instructions to determine the target pump output valuefurther based on the temperature sensor data.
 5. A system forcontrolling output of a fogging array positioned upstream of acombustion turbine, the system comprising: one or more weather sensorsmeasuring one or more conditions of intake air of the combustion turbineand providing weather sensor data responsive to the measurements, theweather sensor data enabling determination of relative humidity of theintake air; a variable output pump supplying liquid to the fogging arraypositioned upstream of the combustion turbine, the variable output pumpoperable at a plurality of speeds; memory storing instructions; acontroller receiving the weather sensor data and coupled to a drive forthe pump, the controller configured to execute the instructions storedin the memory; wherein the instructions comprise instructions to:identify a target humidity value for the intake air; determine, based onthe weather sensor data and the target humidity value, a target pumpoutput value indicative of a pump output required to change the moisturecontent of the intake air to meet the target humidity value; adjust thespeed for the variable output pump based on the target pump outputvalue; determine presence of a leakage condition; and initiate anaudible and/or visible alert in response to determining the presence ofthe leakage condition; wherein the instructions to determine presence ofthe leakage condition comprise instructions to: actuate a plurality ofcontrol valves into a plurality of configurations in which at least onecontrol valve of the plurality of control valves is in an open positionfor each of the plurality of configurations, each of the plurality ofcontrol valves controlling liquid throughput to one or morecorresponding nozzles of the fogging array, for each of the plurality ofconfigurations, compare an actual pressure value, for the liquid in aconduit between the variable output pump and the fogging array, to ananticipated pressure value, and determine the presence of the leakagecondition is at a particular control valve, of the control valves, basedon at least one of the comparisons between the actual pressure value andthe anticipated pressure value.
 6. The system of claim 5, wherein thealert notifies an operator of a location of the leakage condition. 7.The system of claim 5, further comprising: a temperature sensormeasuring temperature of the liquid and generating temperature sensordata, the temperature sensor located upstream of the variable outputpump and measuring the temperature of the liquid before the liquidencounters the variable output pump; wherein the instructions todetermine the target pump output value further comprise instructions todetermine the target pump output value further based on the temperaturesensor data.
 8. The system of claim 5, further comprising: a flow ratesensor located downstream of the variable output pump and in the path ofthe liquid supplied by the pump, the flow rate sensor measuring flow ofthe liquid and providing flowrate sensor data to the controller; whereinthe instructions to determine the target pump output value furthercomprise instructions to determine the target pump output value furtherbased on the flow rate sensor data.